What you do is perfectly fine. AIFF is the standard audio format for uncompressed audio under OS X and is very similar to Microsoft's Wave. FLAC and ALAC are lossless so you won't lose quality while at the same time gain some space.

Antigen: If the hardware used to play the file is soooooo bad that using a tiny percentage of CPU causes noises into the analog component of the soundcard playing it, then it is obvious that the faulty one is the hardware, not the codec.

Sincerely, there are far more reasons to worry about using an uncompressed format than a lossless format.

Philosophically that's equivalent to (and this would likely play well on that site) saying you can hear the difference in someone reading "12" out loud depending on whether the person who wrote 12 on his paper was thinking of it just being 12 or as the result of 6*2.

The entity changing numbers into sound (guy with a sheet of paper or the sound card) is just reading a number and is isolated from how the number was derived.

Many experiments have proven that audible differences that listeners can hear between audio sources are sometimes the product of imagination. These illusions can be strong, durable, shared by many listeners, and consistently associated with the knowledge of the audio source that is listened to.

A Double Blind listening Test (DBT) is a listening setup that allows to confirm that a given audible difference is indeed caused by the audio sources, and not just by the listener's impressions.